Vitaly Kazantsev

After a long time, I decided to repeat the previous experience, but the miracle of history repeated itself. This error falls out no matter what you do. 

Thanks for the reply! Anyway, I didn't fix the error, but I was able to connect playit.gg through their plugin - https://www.spigotmc.org/resources/playit-gg.105566/ Although essentially the same, perhaps I entered something...